A prominent cancer center in Houston has ousted three of five scientists whom federal authorities identified as being involved in Chinese efforts to steal American research.

Peter Pisters, president of MD Anderson Cancer Center, told the Houston Chronicle that the National Institutes of Health wrote to the cancer center last year detailing conflicts of interest and unreported foreign income by five faculty members, and gave it 30 days to respond.

“As stewards of taxpayer dollars invested in biomedical research, we have an obligation to follow up,” Pisters said. MD Anderson received $148 million in NIH grants last year.

The center provided internal documents to the Chronicle regarding the cases but the names of the scientists were redacted. The newspaper said all three are ethnically Chinese. Two of them resigned before termination proceedings and the third is challenging the dismissal.

Officials determined termination was not warranted for one of the remaining two and are still investigating the other.

It’s not clear if any of them face federal charges or deportation. An FBI spokeswoman in Houston, Christina Garza, said Saturday that the agency “does not confirm or deny the existence of any investigation.”

Pisters said MD Anderson’s reputation as the world’s No. 1 cancer center made it an obvious target, but the newspaper report didn’t say what evidence of intellectual property theft was uncovered at the facility.

The dismissals come amid heightened concern in Washington that foreign governments including China have been using students and visiting scholars to pilfer intellectual property from confidential grant applications.

At a gathering in Houston last summer, FBI officials warned Texas academic and medical institutions of the threat, particularly from insiders, and called on them to notify the agency of any suspicious behavior.

A 2017 FBI report found that intellectual-property theft by China costs the U.S. as much as $600 billion annually. FBI Director Christopher Wray has called China “the broadest, most significant” threat to the nation and that its espionage is active in all 50 states.

“This is part of a much larger issue the country is facing,” Pisters told the Chronicle. “Trying to balance an open collaborative environment and at the same time protect proprietary information and commercial interests.”

Some Chinese Americans say the crackdown amounts to racial profiling and that it hinders groundbreaking research.

‘Scientific research depends on the free flow of ideas,” Frank H. Wu, president of the New York-based Committee of 100, a group of influential Chinese Americans, told the newspaper. “Our national interest is best advanced by welcoming people, not by racial stereotyping based on where a person comes from.”